Grease



Patentcd Apr. 25, 1950 UNITED STATES 2.505.222 Gauss Alfred W. Weitkamp, Hammond. Ind., and John C. 'Stamm, Chicago, Ill., asslznors to Standard I(zlilmfloinpany, Chicago, 111., a corporation of No Drawing. Application April as, 1947, Serial No. 744,165

ilClaims.

This invention relates to improved grease compositions and the method of preparing the same. More particularly, the invention relates to improved rosin soap greases and their preparation.

It is the usual practice in preparing rosin soap greases to saponify so-called rosin oils which are viscous distillate oils obtained in the destructive distillation of rosin. The distillation may be carried out by fire in the usual type rosin still, or by fire in the presence of superheated steam. The fractions usually recovered are rosin spirits distilling at about 160 C., a light oil distillate distilling at about 200 C., "kidney 011 distilling at about 250 C. and bloom oil distilling at about 270 C. Heretofore, it has been the practice in the manufacture of soda soap greases, particularly the so-cailed sett greases, to saponify a mixture of rosin oil and petroleum oil of suitable viscosity with a saponiiying agent such as calcium oxide or slaked lime, under such conditions 20 to produce a grease having the desired characteristics. The rosin oil used is the so-called "kidney oil; although, sometimes the so-called bloom" oil is employed. Rosin oil usually employed for this purpose contains about 40 to 50% rosin acids. Although, rosin from which the rosin oil is produced contains more than 90% rosin acids, rosin per se cannot be employed as a substitute for rosin oil in the manufacture of greases, particularly so-called sett greases, since the greases will not set. Therefore, since the value of rosin oil, as a grease component, is in its acid content of 40 to 50%, the remaining 50 to 60% of the neutral oil in the rosin oil is not utilized in the preparation of the soap. Furthermore, the residuum remaining after distilling the rosin oil is not utilized in the grease-making process, and therefore, may be considered wasted.

In order more fully to utilize the rosin, it has been the practice to form a rosin oil in situ by heating a mixture of petroleum oil and rosin at a temperature of about 500 F. to about 510 F. for such a period of time that the rosin oil produced will impart to the grease, upon saponification, the proper setting and consistency characteristics. In the case of sett greases, in order to obtain a rosin oil having the desired characteristics, it is usually necessary to heat the mixture of petroleum oil and rosin for a period of 24 to 44 hours or longer. The duration of heating is determined by sampling the rosin oil periodically, preparing small mixes of greases therefrom and determining the setting' time and penetration thereof. In sett greases the reaction is considered complete when a sett grease prepared from 45 prepared by known methods.

rosin is a product marketed as Resin 731 by the 38T) at a soap content of 8% to 10%. Close control of the heating conditions is necessary since if the temperature is too low, the reaction time becomes excessive, and if the temperature is too high, the rosin acids are rapidly decarboxylated.

10 This prior method of preparing rosin oil results in a diminution of the rosin content from an initial value of about 65% to a final value of about 50%, representing a loss of about 23% of the rosin acids.

It is an object of the present invention to obtain improved rosin soap greases. Another ob- Ject of the invention is to provide an improved method of preparing rosin soap greases. Still another object of the invention is to provide a method of preparing rosin soap greases having desirable characteristics requiring much shorter time in preparation and lower temperatures. Still another object of the invention is to provide improved lime greases and a method of prepar- 25 ing the same. Another object is to increase the yield of rosin greases and to utilize ordinary rosin in the manufacture thereof.

We have discovered that the foregoing objects can be accomplished by employing in the preparation of rosin soap greases mixtures of rosin and hydrogenated and/or dehydrogenated rosin. The hydrogenated rosin may be prepared by known methods; for example, one method of preparing such hydrogenated rosins is described in U. S. Patent 2,399,063, issued to J. M. Schantz,

April 23, 1946. As examples of hydrogenated rosin suitable for use in the present invention is the product marketed as "Stabelite resin, marketed by the Hercules Powder Company, having a melting point of about 168 F. and a flash point of 398 F., an acid number of 162 and an index of refraction at 68 F. of 1.527. Likewise, dehydrogenated rosin suitable for use in the present invention can be any dehydrogenated rosin One such suitable Hercules Powder Company, which is a product obtained by dehydrogenating rosin, and having a melting point of about 2 70 F.

The present invention also contemplates using mixtures'of hydrogenated and dehydrogenated rosins. Mixtures of hydrogenated and dehydrogenated rosins can be prepared by heating rosin with small amounts of sulfur or with active organic sulfur compounds, such as for example sul- I iurized mineral' oil, or natural sulfur-bearing petroleum oils,,at elevated temperatures of about 350 1'. to 525 F. for a short period of time. Methads of so disproportionating rosin are described in copending applications Serial 711,193, flied November 20, 1946, by A. W. Weitkamp, which issued as Patent No. 2,463,823, March 8, 1949, and Serial No. 711,215, filed November 20, 1948, by J. C. Stamm, which issued as Patent No. 2,468,822 on The $er.al No. 711,193, supra, application describes the disproportionation of rosin by heating rosin or a mixture of from about 5% to about 90%, and specifically from about 20% to 50% of a hydrocarbon oil with from about to about. 95%, and preferably from about 50% to,'about resin in the presence of a member of the sulfur group, namely sulfur, selenium or tellurium,

and particularly sulfur at a temperature of from about 350 F. to about 500 F., and preferably irom about 400 F. to about 450 F. for a period of time within the range of from about 0.5 hour to about 12 hours. and preferably from about one hour to about 9 hours, the optimum time being dependent upon the temperature and amount of catalyst used. The catalyst can be used in amounts ranging from about 0.1% to about 5% by weight, and preferably from about 0.25% to about 1.0% by weight. The mineral 011 does not take part in the actual conversion of the original rosin to rosin oil but merely serves as a diluent ior the rosin which by itself is a high melting solid which is dimcult to handle.

in accordance with Serial No. 711,215, supra, application, rosin is disproportionated by heating a mixture of from about 10% to about 90%, and preferably from about 20% to about 50% of an active organic sulfur compound or a mixture of organic sulfur compounds, preferably a sulfurcontainlng hydrocarbon oil such as a sulfurized hydrocarbon oil, Or a natural high sulfur mineral oil, for example a. suitable fraction from Winkler crude or West Texas crude oil, with from about 10% to about 90%, and preferably from about 50% to about 80% of rosin at a temperature of from about 450 F. to about 525 F., and preferably from about 480 F. to about 510 F.

The mixture is heated for a period of time within the range of from about 1 hour to about 12 hours, and preferably from about 3 hours to about 8 hours, the optimum time being dependent upon the temperature and amount and kind of sulfurbearing oil used. A substantially sulfur-free hydrocarbon oil can, if desired, be used in combination with the organic sulfur compound or sulfurcontaining 011.

The rosin used in combination with the hydrogenated and/or dehydrogenated rosin can be any commercial grade of rosin usually used in the preparation of rosin oil for use in manufacturing rosin soap greases. A rosin suitable for this use is the so-called K rosin, a, pale grade rosin.

The relative proportions of rosin and hydrogenated and/or dehydrogenated rosin used in any particular grease product will depend upon the desired setting time and penetration of the grease product. Generally, the ratios of rosin to hydrogenated and/or dehydrogenated rosin of about 6:1 to about 1:4, and preferably 2:1 to 1:2 can be suitably employed. It will be understood that we are not restricted to the foregoing ratios since the ratios of rosin to hydrogenated and/or dehydrogenated rosin which can be used for all greases will vary over a wide range because of differences in the properties required of'the vast number of 4 possible grease product's.- For any particular grease product the ratio of rosin to hydrogenated and/or dehydrogenated rosin required can be best determined by trial. It will be found, however, that a larger proportion of rosin may be used with dehydrogenated rosin than with hydrogenated rosin for a given setting time and penetration. mar example, to prepare a rosin oil equivalent to the prior art rosin oil made from 65 parts 01 rosin with 35 parts of a mineral oil distillate heated to about 500 F. for 24-44 hours, the following compositions can be used:

(a) 16% parts dehydrogenated rosin,

33% parts K rosin, 50 parts mineral oil;

(b) 33% parts hydrogenated rosin,

16% parts K rosin, 50 parts mineral oil.

The compositions (a) and (b) are converted to "rosin oil" by warming and stirring to facilitate solution of the rosin in the oil. The rosin dissolves rapidly at temperatures above its melting point, e. g. about 270 F., but higher or lower temperatures may be used without altering the final product. Convenienttemperatures are in the range of about 150 F. to 300 F. and especially in the range of 180 to 210 F. These improved rosin oils can be used for the purpose of making fluid, semi-solid, or solid greases containing from about 1% to about 50% or more soap, and preferably from about 5% to about 30% rosin soaps, particularly the alkaline earth, or alkali metal rosin soaps, such as for example calcium, barium, sodium, lithium, and strontium rosin soaps, as well as nitrogen base soaps or mixtures thereof. The present invention contemplates also the use of heavy metal rosin soaps of rosin oil prepared in accordance with the present invention.

The present invention is particularly well adapted to the preparation of sett greases which are mixtures of calcium soaps of rosin acids and various grades of mineral lubricating oils. Sett greases which usually contain from about 5% to about 25% calcium rosin soap are generally employed for the lubrication of rough heavy bearings operating at low speed and are used extensively in the logging industry where a relatively cheap grease is required for the lubrication of skidways. The following procedure illustrates one method of applying the present invention to the properation of sett greases, in which a mixture of rosin and dehydrogenated rosin is employed. A mixture of 16% parts dehydrogenated rosin, 33%; parts K rosin and 50 parts of mineral oil of about seconds Saybolt Universal viscosity at F. is heated in a steam-heated kettle to a temperature of about 180 to about 200 F. until the rosins are dissolved. A grease prepared from about 15% of the rosin oil thus formed, 75% mineral oil, 7% water and 3% calcium hydrate gels in about 20 to 40 seconds and has an unworked penetration of to mm. at 77 F. by the ASTM Cone Penetrometer Test.

One method of preparing this grease is to dilute the 15 parts of rosin oil with about 50 parts of the mineral oil. The remaining 25 parts of mineral oil are made into a smooth paste by stirring with 3 parts of calcium hydrate and 7 parts of water. The rosin oil solution is then continuously mixed at about 90-110 F. with the lime slurry, agitated thoroughly for 10-15 seconds and immediately filled into cans. Within 20-40 seconds the containers may be covered and packaged many hours, it at all.

.without danger oi deiormlns r spilling the grease. Y

The petroleum oilused in rosin soap greases in accordancewith the present invention canbe a distillate or residuum oil from parafiinic, ,naphthenic, asphaltic or mixed crude oils and may range in viscosity from about 70 to about 500 ormore seconds Saybolt Universal at 100 F.

The advantage of using a mixture 0! rosin and Per Cent got? 8 till Per Cent 93 n e 77 Pene- Soapv tration the Rosin oil The above data demonstrate that the present invention makes it possible to prepare greases with the same penetration of the prior art methods at the same soap content but requiring substantially less total rosin acids and having a substantially lower sett or gelling time.

Using hydrogenated rosin or dehydrogenated rosin or mixtures thereof without rosin results in grease products having setting times so'short that it is not possible to adequately mix the materials to obtain homogeneous products by a cold sett method. Thus, a calcium rosin soap grease containing only hydrogenated rosin has a. sett time of 9 seconds, while a similar grease made from dehydrogenated rosin has a sett time of 4'seconds; both sett times being too rapidfor proper mixing. On the other hand, a similar grease prepared from rosin alone will not sett or gel over a period of The present invention has none of the disadvantages of the prior art processes. In the present invention a 100% yield on rosin acids is obtained instead oi about '77 The present invention employs lower temperatures, i. e. 150-200 F. and short mixing times, instead of the high temperatures, i. e. 500-510 F. and long reaction times, i. e. 24-44 hours of the prior methods. At th lower temperatures corrosion difllculties and fire hazards are virtually eliminated. Other advantages are flexibility of the process in that the setting or gelling time of the batch can be readily changed by varying the proportions of rosin and hydrogenated and/or dehydrogenated rosin. The finished rosin oil of the present invention has a clear amber color instead of the dark brownto black color of the prior art product.

when used herein and in the claims proportions and percentages are on a weight basis.

It will be understood that grease products made in accordance with. the present invention can contain, if desired, graphite, mica, talc. antioxidants, leak inhibitors, extreme pressure agents, etc.

While we have described the preferred embodiments or our invention and the preferred mode of carrying out the same, it will be apparent from the spirit of-the' invention, the scope of which is limited only by the-appended claims.

We claim: i

1. The method of preparing a rosin soap grease comprising heating a mixture of a hydrocarbon oil, rosin, and a modified rosin oi the group consisting of dehydrogenated rosin, hydrogenated rosin, and mixtures thereof, at a temperature of from about F. to about 300 F., to eflect the solution of said rosin and said modified rosin in said hydrocarbon oil, and subsequently saponiiying the solution of oil, said rosin and said modified rosin with a saponiiying agent, selected from the group consisting of an alkali metal base, an alkaline earth base, and mixtures thereof, said rosin and modified rosin being used in the ratio of from 6:1 to about 1:4.

2. The method of claim 1 in which the saponii'ying agent is sodium hydroxide.

3. The method of claim 1 in which the saponitying agent is calcium hydroxide.

4. The method of claim 1 in which the saponifying agent is calcium hydrate.

5. The method or preparing a rosin soap grease comprising mixing rosin and a dehydrogenated v rosin in the ratio of about 2:1 with a hydrocarbon oil, heating the mixture to a temperature of from about 150 F. to about 300 F., until a homogeneous solution of said hydrocarbon oil, said rosin and said dehydrogenated rosin is obtained, and subsequently saponifying said solution with a saponiiying agent selected from the group consisting of an alkali metal base, an alkaline earth base and mixtures thereof.

6. The method of preparing a rosin .soap grease comprising mixing rosin and a hydrogenated rosin in the ratio or about 1:2 with a hydrocarbon oil, heating the mixture to a temperature of from about 150 F. to about 300 F. until a homogeneous solution of said hydrocarbon oil, rosin and hydrogenated rosin is obtained, and subsequently saponii'ying the solution with a saponiiying agent selected from the group consisting of an alkali metal base, an alkaline earth base, and mixtures thereof.

7. The method of preparing an alkaline earth rosin soap grease comprising mixing rosin and a modified rosin selected from the group consisting of dehydrogenated rosin, hydrogenated rosin and mixtures thereof, in the ratio of about 6:1 to about 1:4, and a hydrocarbon oil, heating the mixture to a temperature of from about 150 F. to about 300 F., until the homogeneous solution of said hydrocarbon oil, rosin and modified rosin is obtained, and then saponiiying the solution with an alkaline earth base.

8. In the preparation of a sett grease containing from about 1% to about 50% calcium rosin soap, wherein a rosin soap is prepared by saponiiying rosin with calcium hydrate, the improvement comprising forming a homogeneous mixture of a hydrocarbon oil and a mixture of rosin and a modified rosin of the group consisting of dehydrogenated rosin, hydrogenated rosin, and mixtures thereof, in the ratio of from about 6:1 to about 1:4, by heating the mixture to a temperature of from about 150 F. to about 300 F., to effect the solution of said rosin, and modified rosin in said hydrocarbon oil, and subsequently saponii'ying said solution with calcium hydrate.

9. In the preparation 01' a-sett grease contain lng calcium rosin soap, the improvement'comprising heating a mixture of a hydrocarbon oil,

7 I I rosin, a modined resin or the group consisting o! dehydrogenated rosin. hydrogenated rosin, and

mixtures thereof, said rosin and modified rosinbeing used in the rctio of from about 8:1 to about 1:4, to a temp/fixture 01' from about 150' I. to about 390:2. til a. homogeneous solution of said hydrocarbon oil, rosin and modified rosin is obtained, mixing 15 parts of said solution with 50 parts of a. viscous hydrocarbon oil and uponflying said mixture at a. temperature-o! from 10 about 90 F. to about 110 F. with a mixture comprising 25 parts of a viscous hydrocarbon oil, 3

parts calcium hydrate, and 7 parts water.

ALFRED W. JOHN C. BTAMM.

l nu-muons crrm The following references are of record in the file of this patent:

I I UNITED STATES PATENTS Number Name at 2,042,035 Brennan May 26, 1936 2.071.488 Zimmer Feb. 23. 1937 2,103,209 Lister Dec. 21, 1937 I 2,281,022 Merrill Feb. 11, 1941 2,235,926 Hasselstrom Mar. 25. 1941 2,323,471 Humphrey July 8, 1943 2,399,063 Bchantz Apr. 23, 1946 

1. THE METHOD OF PREPARING A ROSIN SOAP GREASE COMPRISING HEATING A MIXTURE OF A HYDROCARBON OIL, ROSIN, AND A MODIFIED ROSIN OF THE GROUP CONSISTING OF DEHYDROGENATED ROSIN, HYDROGENATED ROSIN, AND MIXTURES THEREOF, AT A TEMPERATURE OF FROM ABOUT 150*F. TO ABOUT 300*F., TO EFFECT THE SOLUTION OF SAID ROSIN AND SAID MODIFIED ROSIN IN SAID HYDROCARBON OIL, AND SUBSEQUENTLY SAPONIFYING THE SOLUTION OF OIL,, SAID ROSIN AND SAID MODIFIED ROSIN WITH A SAPONIFYING AGENT, SELECTED FROM THE GROUP CONSISTING OF AN ALKALI METAL BASE, AN ALKALINE EARTH BASE, AND MIXTURES THEREOF, SAID ROSIN AND MODIFIED ROSIN BEING USED IN THE RATIO OF FROM 6:1 TO ABOUT 1:4. 